The present invention relates to a retaining structure for earthen formations and, more particularly, is concerned with a method and apparatus for providing such a structure which serves to anchor face elements to the formation and accommodate relative movement between these elements and anchoring or reinforcement elements embedded within the formation. In its more specific aspects, the invention is concerned with such a method and apparatus for securing rigid face elements in place upon a foundation in such a way that movement of the formation as the result of earthquake or settling does not impart destructive forces to the face elements or the anchoring means therefor.
The problem of accommodating relative movement between rigid face elements for a retaining wall structure and the anchor means for the elements was dealt with in U.S. Pat. No. 1,762,343 to Munster. In the structure of that patent, vertically extending ribs were formed on the face elements and the anchor members were slidably connected to these ribs for movement relative thereto to accommodate settling of the earthen formation. The structure required that special ribs be formed on the face elements and depended upon maintaining a slidable connection between these ribs and the anchoring elements. Once the structure of the patent was in place and fully loaded, it is doubtful that such a slidable connection could be maintained.
Other prior art efforts have accommodated for relative movement between the face members of a retaining structure and anchoring means therefor by fabricating the face members as flexible cladding which is relatively free to move in the event that the earthen formation settles. Such teachings are found, for example, in U.S. Pat. Nos. 3,421,326 and 3,686,873 to Vidal. Still other efforts to accommodate settling in earthen formation retaining structures have relied on the employment of retaining structures which are comprised entirely of flexible wire grid elements. Such efforts are found in the relatively ancient gabions, as well as some relatively recent efforts which employ wire grid works which serve to provide both earth reinforcement and a face for the earthen formation being reinforced. Examples of the latter recent efforts may be found in my prior U.S. Pat. No. 4,117,686 and in French Pat. No. 7,507,114 to Vidal.
The present invention is designed primarily for use with earthen retaining structures wherein foundation supported relatively rigid face members are employed. To that extent, of the above discussed patents, U.S. Pat. No. 1,762,343 is thought to be the most significant.